The correct answer is D.

The Advanced Measurement Approach (AMA) is a methodology introduced under Basel II specifically for calculating the capital requirements for Operational Risk, not credit risk.

To calculate Credit Risk capital under Basel II, banks can use one of the following three approaches:

1. Standardized Approach
2. Foundation Internal Ratings-Based (F-IRB) Approach
3. Advanced Internal Ratings-Based (A-IRB) Approach